Applicant believes that the closest reference corresponds to a seminar that took place in San Francisco and sponsored by the American College of Allergy & Immulogy (47th Annual Meeting) in November of 1990 (lecturers: J. E. Postley, M. D. and J. Einbinder, PhD) wherein it was discussed that IgAs can be obtained from the saliva to make certain determinations concerning the presence of antigens/antibodies. The method disclosed, however, required the production of approximately 30 cc of saliva from a patient in order to obtain IgAs in the micro-grams range. The unreliability of using any conventional diagnosis method from these minimal quantities of IgAs is quite apparent. Also, the undesirability of the method from the patient's standpoint is obvious.
To determine the presence of antigens and/or antibodies many conventional methods have been used in the past. Most of them, using an enzyme conjugated with another chemical substance to detect the presence, and with some methods, approximate the quantity of the antigens and antibodies. Typically, these methods are used in conjunction with blood drawn from the patient and the immunoglobin classes tested are the IgE and IgG4. However, IgAs is not present in the blood drawn from an individual in appreciable quantities since it is mainly created by the mucous, such as the intestines' mucous membranes, and being eventually stored in the feces. The information carried in general immunity IgE and IgG4 is not as relevant for diagnostic purposes as the information included in the local immunity IgAs. The conventional methods include those that use conjugated enzymes, such as, ELISA, RIA, radio immuno assay, immunoofluorescent methods, dots/disks, strips methods, etc. None of these methods are directed towards the use of IgAs since it is not present in the blood drawn from the patient in appreciable quantifies.
None of the methods presently used for detection of the presence of antigens and/or antibodies utilize IgMs because it is not found in the blood in sufficient amounts. However, when used with IgAs it provides valuable information in the diagnostis of diseases caused by bacterias, viruses and certain tumural lesion on the digestive tract.